Cooling unit for rectifier module

Abstract

To provide a cooling unit for a rectifier module.SOLUTION: A cooling unit 100 of a rectifier module includes: an element body 11 having first and second transistors Q1, Q2 that are arranged therein, have first and second source terminals S1, S2 and first and second drain terminals D1, D2, and perform a switching operation; a rectifier module 10 having a first module terminal 12c and a second module terminal 13; a substrate 20 on which the first module terminal 12c is attached so as to extend vertically with respect to a substrate surface 21; a first conductive cooling portion 30; a second conductive cooling portion 40; and a cooling promoting portion 50. A part of a first current path 60 of first current is constituted by a first penetration current path 61 that penetrates the substrate 20 from the substrate surface 21 to a substrate back surface 22, and a part of a second current path 70 of second current is constituted by a second conductive cooling path 72 that passes through the second conductive cooling portion 40 without passing through the substrate 20.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a cooling unit for a rectifier module. [Background technology]

[0002] A power conversion device includes, for example, a primary circuit that receives an input voltage, a secondary circuit that outputs an output voltage, and a transformer that magnetically connects the primary circuit and the secondary circuit. The secondary circuit is provided with a rectifier circuit that rectifies the voltage waveform generated in the secondary winding of the transformer. A large current flows through this rectifier circuit, which generates heat. The heat can cause damage to elements that configure the rectifier circuit, so it is necessary to cool the rectifier circuit.

[0003] Patent Document 1 discloses a power conversion device including a transformer, a rectifying element constituting a rectifying circuit on the secondary side of the transformer, a choke coil constituting a smoothing circuit on the secondary side of the transformer, and a housing in which the choke coil is installed and which has a cooling unit. The housing has a water channel as a cooling unit formed below and a pair of standing parts standing upright with respect to the water channel. With the choke coil sandwiched inside the pair of standing parts, a metal substrate is arranged along the outer surface of each standing part. A rectifying element is arranged on each of these metal substrates. Heat generated in the rectifying element and the metal substrate is dissipated to the water channel via each standing part, thereby cooling the rectifying element and the metal substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-144238 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration of Patent Document 1, although the heat generated by the rectifier element and the metal substrate can be dissipated, the heat generation in the metal substrate itself cannot be suppressed. In other words, the large current flowing through the rectifier element is taken out through the metal substrate, so that the large current flows through the metal substrate. Therefore, the metal substrate generates a large amount of heat, and there is a risk that the heat generated by the metal substrate may cause the rectifier element to be destroyed. Therefore, there is a demand for an improvement in the cooling structure of the rectifier circuit.

[0006] SUMMARY OF THE PRESENT EMBODIMENTS Therefore, a primary object of the present invention is to provide a cooling unit for a rectifier module. [Means for solving the problem]

[0007] The cooling unit for a rectifier element module according to the present invention comprises a rectifier element module having an element body having a first element terminal and a second element terminal and having a rectifier element disposed therein for generating a rectified output voltage by a switching operation based on a voltage difference between the first element terminal and the second element terminal, a first module terminal electrically connected to the first element terminal and extending from a portion of the element body other than the rear surface of the element body along the rear surface of the element body to the outside of the element body, and a second module terminal electrically connected to the second element terminal and disposed with at least a portion in contact with the rear surface of the element body, and a cooling unit for a rectifier element module having a first module terminal and a second module terminal electrically connected to the second element terminal and disposed with at least a portion in contact with the rear surface of the element body, the rectifier element module being disposed on the substrate surface side and the first module terminal being attached so as to extend perpendicular to the substrate surface. the rectification element module includes a substrate having an element body and a second module terminal spaced apart from the substrate surface; a first conductive cooling section electrically connecting the first module terminal to a first external member arranged externally to the cooling unit of the rectification element module, and primarily cooling heat generated by a first current passing through the first element terminal; the first conductive cooling section is an insulated conductive cooling section, and a second conductive cooling section electrically connecting the second module terminal to a second external member arranged externally to the cooling unit of the rectification element module, and primarily cooling heat generated by a second current passing through the second element terminal; and a cooling promotion section in which at least one of the first conductive cooling section and the second conductive cooling section is arranged directly or indirectly, and which promotes cooling of at least one of the arranged sections. The first conductive cooling part is disposed in contact with the rear surface of the substrate, the second conductive cooling part is disposed on the front surface side of the substrate, and the second module terminal is disposed in contact with the second conductive cooling part. A portion of the first current path of the first current that runs from the first element terminal through the first module terminal and the first conductive cooling part to the first external member is composed of a first through current path that passes through the substrate from the front surface to the back surface of the substrate. A portion of the second current path of the second current from the second element terminal through the second module terminal and the second conductive cooling part to the second external member is composed of a second conductive cooling path that passes through the second conductive cooling part without passing through the substrate.

[0008] According to the above configuration, it is possible to provide a cooling unit for a rectifying element module for cooling a substrate and a rectifying element. Effect of the Invention

[0009] According to the present invention, it is possible to provide a cooling unit for a rectifier module.

[0010] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention, which refers to the drawings. [Brief description of the drawings]

[0011] [Figure 1] 2 is a side view of a cooling unit of the rectification element module according to the embodiment of the present invention; FIG. [Diagram 2] 2 is a top view of a cooling unit of the rectification element module according to the embodiment of the present invention; FIG. [Diagram 3] 1 is a circuit diagram of a power conversion device having a synchronous rectification circuit. [Figure 4] FIG. 2A is a top perspective view of a rectifying element module, and FIG. 2B is a rear perspective view of FIG. [Diagram 5] 2 is a current path diagram showing the flow of current in a cooling unit of the rectifier module of FIG. 1. [Figure 6A] 10 is a side view of a cooling unit of a rectification element module of another aspect 1 according to an embodiment of the present invention. FIG. [Figure 6B] 13 is a side view of a cooling unit of a rectification element module of another aspect 2 according to an embodiment of the present invention. FIG. [Figure 6C] 13 is a side view of a cooling unit of a rectification element module of another aspect 3 according to an embodiment of the present invention. FIG. [Figure 7] 1 is a circuit diagram of a power conversion device having a synchronous rectifier circuit of another configuration 1. FIG. [Figure 8] 11 is a circuit diagram of a power conversion device having a synchronous rectifier circuit of another configuration 2. FIG. [Figure 9] 11 is a circuit diagram of a power conversion device having a synchronous rectifier circuit of another configuration 3. FIG. [Figure 10] 11 is a circuit diagram of a power conversion device having a synchronous rectifier circuit of another configuration 4. FIG. [Figure 11] 1 is a circuit diagram of a power conversion device having a rectifier circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] 1. Embodiment (1) Configuration of the cooling unit for the rectifier module The configuration of a cooling unit 100 for a rectification element module according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a side view of a cooling unit of a rectifying element module according to an embodiment of the present invention, and Fig. 2 is a top view of the cooling unit of a rectifying element module according to an embodiment of the present invention.

[0013] The cooling unit 100 of the rectifier module includes a rectifier module 10, a substrate 20, a first conductive cooling section 30, a second conductive cooling section 40, and a cooling promotion section 50. The rectifier module 10 generates a rectified output voltage. The rectifier module 10 is disposed on the substrate 20. The first and second conductive cooling sections 30, 40 electrically transmit signals in the rectifier module 10 and cool the rectifier module 10 and the substrate 20. In FIG. 1, FIG. 2, etc., the direction in which the first and second conductive cooling sections 30, 40 are arranged is the x direction. The direction perpendicular to the x direction is the y direction. The direction perpendicular to the x direction and the y direction is the z direction, and may be referred to as the vertical direction, up, or down. In this embodiment, the substrate 20 extends in the z direction. In addition, a plane parallel to the xy plane is referred to as a horizontal plane, and a direction along the horizontal plane is referred to as a horizontal direction. In addition, a plane perpendicular to the xy plane is referred to as a vertical plane. Each part is explained below.

[0014] The rectifier module 10 has therein a rectifier for generating a rectified output voltage. The rectifier constitutes a synchronous rectifier circuit. Such a synchronous rectifier circuit is used in the power conversion device 1. Fig. 3 is a circuit diagram of a power conversion device having a synchronous rectifier circuit.

[0015] There are many types of power conversion devices using a synchronous rectifier circuit, but as an example, a midpoint tap type power conversion device 1 will be described here. As shown in FIG. 3, the power conversion device 1 includes a transformer 2, a primary circuit 3, and a secondary circuit 4. The primary circuit 3 generates an AC voltage from a DC voltage and supplies the AC voltage to a primary winding 2b of the transformer 2. A magnetic field is generated by a current flowing through the primary winding 2b, and a current is induced in the secondary windings 2c and 2d (an example of a second external member in this embodiment) of the transformer 2 by electromagnetic induction of this magnetic field. As a result, an output voltage according to a turn ratio is obtained from the secondary windings 2c and 2d.

[0016] The transformer 2 has a core 2a, a primary winding 2b, and secondary windings 2c and 2d. The primary winding 2b is wound around the core 2a from a primary winding start end 2b1 to a primary winding end 2b2. The secondary windings 2c and 2d are wound around the core 2a, and have a first partial winding 2c and a second partial winding 2d. The first partial winding 2c is wound around the core 2a from a first partial winding start end 2c1 to a first partial winding end 2c2. The second partial winding 2d is wound around the core 2a from a second partial winding start end 2d1 to a second partial winding end 2d2. In addition, the first partial winding end 2c2 and the second partial winding start end 2d1 are connected so that the first partial winding 2c and the second partial winding 2d are in series. The first partial winding start end 2c1 and the second partial winding end end 2d2 are connected to a secondary output (-) line Vout(-) (an example of a first external member in this embodiment) via a secondary circuit 4. The connection portion between the first partial winding end end 2c2 and the second partial winding start end 2d1 is commonly connected to a secondary output (+) line Vout(+). An output voltage induced in the first partial winding 2c and the second partial winding 2d is output from the secondary output (+) line Vout(+).

[0017] The primary circuit 3 is not limited as long as it can receive a DC voltage input from the primary input (+) line Vin(+) and the primary input (-) line Vin(-) and generate an AC voltage from the DC voltage. For example, the primary circuit 3 has a plurality of transistors that receive a DC voltage from the primary input (+) line Vin(+) and the primary input (-) line Vin(-). By switching the plurality of transistors, the primary circuit 3 can generate an AC voltage from the DC voltage.

[0018] The secondary circuit 4 rectifies the output voltage induced in the secondary windings 2c, 2d. The secondary circuit 4 has first and second transistors Q1, Q2 (an example of a rectifying element). The first transistor Q1 has a first gate terminal G1, a first source terminal S1 (an example of a first element terminal), and a first drain terminal D1 (an example of a second element terminal). The second transistor Q2 has a second gate terminal G2, a second source terminal S2 (an example of a first element terminal), and a second drain terminal D2 (an example of a second element terminal). A first gate signal g1 is input to the first gate terminal G1, and a second gate signal g2 is input to the second gate terminal G2. The first and second drain terminals D1, D2 are connected to the secondary windings 2c, 2d (an example of a second external member in this embodiment). Specifically, the first drain terminal D1 is connected to the second portion winding end 2d2, and the second drain terminal D2 is connected to the first portion winding start end 2c1. The first and second source terminals S1 and S2 are commonly connected to the secondary output (-) line Vout(-).

[0019] In such a secondary circuit 4, the first and second transistors Q1 and Q2 perform switching operations based on the voltage difference applied to the first and second gate terminals G1 and G2, the first and second source terminals S1 and S2, and the first and second drain terminals D1 and D2. In the example of FIG. 3, the first and second transistors Q1 and Q2 alternately turn on and off. As a result, the output voltage from the first partial winding 2c and the output voltage from the second partial winding 2d are alternately output from the secondary output (+) line Vout(+), and as a result, a rectified output voltage is output from the secondary output (+) line Vout(+). In this embodiment, the first and second transistors Q1 and Q2 form a synchronous rectification circuit.

[0020] Furthermore, the secondary side circuit 4 may include a circuit related to rectification, such as a smoothing circuit, in addition to a synchronous rectifier circuit (an example of a rectifier circuit).

[0021] In the present embodiment, the transistor is, for example, a MOSFET transistor (metal oxide semiconductor field effect transistor). However, an IGBT (insulated gate bipolar transistor) or the like can be used instead of the MOSFET transistor.

[0022] Next, a rectifier module 10 having first and second transistors Q1 and Q2 (an example of a rectifier) ​​will be described. In Fig. 4, (a) is a top perspective view of the rectifier module, and (b) is a rear perspective view of (a).

[0023] As shown in FIG. 4, the rectifier module 10 has an element body 11, a first lead terminal 12, and a second module terminal 13. The element body 11 has a transistor (first transistor Q1 or second transistor Q2) disposed therein and is configured by sealing the transistor with resin. The element body 11 has an element body rear surface 11a, an element body front surface 11b, and an element body side surface 11c. In this embodiment, the element body 11 has a roughly rectangular parallelepiped shape, the element body rear surface 11a is the rear surface of the element body 11, the element body front surface 11b is the front surface of the element body 11 facing the element body rear surface 11a, and the element body side surface 11c is the side surface excluding the element body rear surface 11a and the element body front surface 11b.

[0024] In the following, the rectifier module 10 will be described on the assumption that the first transistor Q1 is disposed inside the element body 11.

[0025] In this embodiment, a first lead-out terminal 12 extends from the element body 11. The first lead-out terminal 12 is formed of a conductive material, for example, a metal containing copper as a main component. The first lead-out terminal 12 has a gate pin 12a, an unused pin 12b, and a first module terminal 12c. The gate pin 12a, the unused pin 12b, and the first module terminal 12c are aligned in order in a direction along the element body back surface 11a. The unused pin 12b is cut and is not used. The first module terminal 12c is electrically connected to the first source terminal S1. The gate pin 12a is electrically connected to the first gate terminal G1. The gate pin 12a and the first module terminal 12c extend from one of the element body side surfaces 11c to the outside of the element body 11 along the element body back surface 11a. Furthermore, one of the element body side surfaces 11c from which the gate pin 12a and the first module terminal 12c are drawn out is a surface facing the side from which a part of the second module terminal 13 protrudes from the element body 11. In other words, the direction in which the first drawn-out terminal 12 extends from the element body 11 faces the direction in which the second module terminal 13 protrudes from the element body 11. For ease of explanation, only the first module terminal 12c of the first drawn-out terminal 12 is shown in Fig. 1 etc.

[0026] The second module terminal 13 is electrically connected to the first drain terminal D1. At least a portion of the second module terminal 13 is disposed in contact with the element body rear surface 11a. In this embodiment, the second module terminal 13 is in the form of a plate extending along the element body rear surface 11a, and a portion of the second module terminal 13 is disposed in surface contact with the element body rear surface 11a. The second module terminal 13 is disposed so as to be flush with the element body rear surface 11a. The remaining portion of the second module terminal 13 that is not in contact with the element body rear surface 11a extends from one of the element body side surfaces 11c toward the opposite direction to the direction in which the first module terminal 12c extends from the element body 11 to the outside of the element body 11 while following the element body rear surface 11a. The portion of the second module terminal 13 that extends to the outside of the element body 11 is provided with a fastening hole 13a into which a fastener (not shown) for attaching the rectifier element module 10 to the substrate 20 can be inserted. Such a second module terminal 13 is formed of a conductive material, for example, a metal mainly composed of copper.

[0027] In the above rectifier module 10, the first module terminal 12c extends to the outside of the element body 11 along the element body back surface 11a, and at least a part of the second module terminal 13 is disposed along the element body back surface 11a. The above rectifier module 10 is, for example, a discrete component in a standard state in which the first module terminal 12c extends to the outside of the element body 11 without being bent. The standard state in which the first module terminal 12c is not bent is, for example, a state in which the standard state of the discrete component in which the first module terminal 12c extends to the outside from the element body 11 while remaining along the element body back surface 11a is maintained. In addition, the state in which the first module terminal 12c is not bent also includes a state in which the first module terminal 12c is not bent to an extent toward the element body back surface 11a from the standard state of the discrete component, but is slightly bent in a direction not along the element body back surface 11a. In the present embodiment, the standard state is one in which the first module terminal 12c extends along the element body rear surface 11a to the outside of the element body 11. In the present embodiment, the gate pin 12a also extends along the element body rear surface 11a to the outside of the element body 11, similar to the first module terminal 12c.

[0028] As shown in FIG. 1 and FIG. 2, the substrate 20 is for disposing the rectifying element module 10. The substrate 20 is formed in a plate shape and has a substrate surface 21 and a substrate back surface 22. The substrate 20 is provided upright with respect to the cooling promotion unit 50. Here, the substrate 20 is provided upright in the vertical direction. Therefore, the substrate surface 21 and the substrate back surface 22 are along a vertical plane. The rectifying element module 10 is provided on the substrate surface 21 side of the substrate 20. The first module terminal 12c extends in a direction perpendicular to the substrate surface 21 (here, the x direction) and is attached to the substrate 20 at the first attachment portion 25. Furthermore, the first module terminal 12c is inserted into a pin hole described later from the substrate surface 21 to the substrate back surface 22, penetrating the substrate 20, and is electrically connected to the first conductive cooling unit 30. Although the gate pin 12a is omitted in FIG. 1, it extends in a direction perpendicular to the substrate surface 21 and is attached to the substrate 20, similar to the first module terminal 12c. The gate pin 12a is electrically connected to a gate signal circuit (not shown) via, for example, a wiring (not shown) on the substrate 20, and receives a first gate signal g1.

[0029] In this embodiment, the element body 11 and the second module terminal 13 are spaced upward from the substrate surface 21. Here, the first module terminal 12c is attached to the substrate surface 21 in a standard state in which it extends along the element body rear surface 11a. Therefore, the element body 11 and the second module terminal 13 are located on the side away from the substrate 20 with respect to the first mounting portion 25 where the first module terminal 12c is attached to the substrate 20.

[0030] The substrate 20 is provided with at least one pin hole (not shown) penetrating the substrate 20 from the substrate front surface 21 to the substrate rear surface 22. At least one pin hole is provided corresponding to the first module terminal 12c. At least one pin hole may be provided corresponding to each of the unused pins 12b and the gate pins 12a. The peripheral surface of the pin hole may be coated with a metal such as Cu, Ni, Sn, etc., by plating or the like. The first module terminal 12c is inserted into the pin hole and soldered, and the rectifier module 10 is fixed to the substrate 20. The first module terminal 12c penetrates the substrate 20 through the pin hole and is electrically connected to the first conductive cooling unit 30 located on the substrate rear surface 22.

[0031] A relatively inexpensive resin substrate such as glass epoxy resin, a ceramic substrate, etc. can be used as the substrate 20. Furthermore, the substrate 20 can be relatively thin, having a thickness of, for example, 1.6 mm or more and 2.0 mm or less.

[0032] On the substrate 20, various electronic components other than the rectifying element module 10 and wiring other than the wiring for the rectifying element module 10 may be arranged.

[0033] In the example of FIG. 1, the first conductive cooling part 30 electrically connects the secondary output (-) line Vout(-) (an example of a first external member in this embodiment) arranged externally to the cooling unit 100 of the rectifier element module to the first module terminal 12c. The first conductive cooling part 30 is arranged in contact with the back surface 22 of the substrate. Here, as described above, the first module terminal 12c is electrically connected to the first conductive cooling part 30 in a state where it is inserted into a pin hole penetrating the substrate 20 and fixed. For example, the tip of the first module terminal 12c protrudes toward the back surface 22 of the substrate 20, and is electrically connected to the first conductive cooling part 30 by contacting this protruding part. And, since the first conductive cooling part 30 is electrically connected to the secondary output (-) line Vout(-), the secondary output (-) line Vout(-) and the first module terminal 12c are electrically connected via the first conductive cooling part 30. When the rectifier module 10 includes the first transistor Q1, the first source terminal S1 and the secondary output (−) line Vout(−) are electrically connected via the first conductive cooler 30.

[0034] Furthermore, when the rectifier module 10 has the first transistor Q1, the first conductive cooling unit 30 mainly cools the heat generated by the first current passing through the first source terminal S1. Since a relatively large first current flows through the rectifier module 10, the heat generated by the first current is also relatively large. The heat generated by the first current may be generated in the rectifier module 10 or in the substrate 20 through which the first current passes. The first conductive cooling unit 30 can cool the heat generated by the substrate 20 and the rectifier module 10 due to the first current.

[0035] A material having electrical conductivity and a cooling function is used for the first conductive cooling member 30. The first conductive cooling member 30 is made of a metal such as Cu or Al.

[0036] In the example of FIG. 1, the second conductive cooling part 40 electrically connects the secondary windings 2c, 2d (an example of a second external member in this embodiment) arranged externally to the cooling unit 100 of the rectifier module to the second module terminal 13. Specifically, when the rectifier module has a first transistor Q1, the second conductive cooling part 40 electrically connects the first drain terminal D1 to the second partial winding end 2d2 of the second partial winding 2d (an example of a second external member in this embodiment). The second conductive cooling part 40 is arranged on the substrate surface 21 side, similar to the rectifier module 10. The second module terminal 13 is attached in contact with the second conductive cooling part 40. This contact part is hereinafter referred to as the second attachment part 26.

[0037] Furthermore, when the rectifier module 10 has the first transistor Q1, the second conductive cooling unit 40 mainly cools the heat generated by the second current passing through the first drain terminal D1. Since a relatively large second current flows through the rectifier module 10, the heat generated by the second current is also relatively large. The heat generated by the second current may be generated in the rectifier module 10 or in the substrate 20 through which the second current passes. The second conductive cooling unit 40 can cool the heat generated by the substrate 20 and the rectifier module 10 due to the second current.

[0038] A material having electrical conductivity and a cooling function is used for the second conductive cooling member 40. The second conductive cooling member 40 is made of a metal such as Cu or Al.

[0039] At least one of the first and second conductive cooling parts 30, 40 is directly or indirectly arranged on the cooling promotion part 50, and promotes the cooling of at least one of the arranged conductive cooling parts 30, 40. In the example of FIG. 1, the cooling promotion part 50 has an arrangement surface 51 which is a horizontal surface and is the upper surface of the cooling promotion part 50. The first conductive cooling part 30 is arranged in contact with the rear surface 22 of the substrate and in contact with the arrangement surface 51 of the cooling promotion part 50. The second conductive cooling part 40 is indirectly arranged on the arrangement surface 51 of the cooling promotion part 50 in a state insulated from the cooling promotion part 50 via the insulating member 80. Therefore, the first conductive cooling part 30 and the second conductive cooling part 40 are electrically insulated from each other. This prevents the first module terminal 12c and the second module terminal 13 from shorting out with each other. In the example of FIG. 1, the cooling promotion part 50 is in contact with the first conductive cooling part 30 and directly promotes the cooling of the first conductive cooling part 30. On the other hand, the cooling promotion part 50 indirectly promotes the cooling of the second conductive cooling part 40 via the insulating member 80. The substrate 20 is placed on the placement surface 51 in a state insulated from the cooling promotion part 50 via the insulating member 80.

[0040] The cooling promotion part 50 is not limited in configuration as long as it can promote the cooling of the first and second conductive cooling parts 30, 40. Examples of the cooling promotion part 50 include a water-cooled heat sink composed of one or more fins and conduits capable of passing liquid such as water, and an air-cooled heat sink composed of one or more fins capable of dissipating heat.

[0041] Note that the above explanation was given in relation to a rectifier module 10 in which a first transistor Q1 is arranged, but below we will briefly explain a rectifier module 10 in which a second transistor Q2 is arranged, focusing on the differences.

[0042] The first module terminal 12c is electrically connected to the second source terminal S2. The gate pin 12a is electrically connected to the second gate terminal G2. The second module terminal 13 is electrically connected to the second drain terminal D2.

[0043] The first module terminal 12c extends perpendicular to the substrate surface 21, penetrates the substrate 20, and is electrically connected to the first conductive cooling part 30. The gate pin 12a extends perpendicular to the substrate surface 21, and is electrically connected to a gate signal circuit (not shown), for example, via wiring (not shown) on the substrate 20, and is supplied with a second gate signal g2.

[0044] The first conductive cooling unit 30 electrically connects the second source terminal S2 to the secondary output (-) line Vout(-) (an example of a first external member in this embodiment) and mainly cools the heat generated by the first current passing through the second source terminal S2. The second conductive cooling unit 40 electrically connects the second drain terminal D2 to the first partial winding start end 2c1 of the first partial winding 2c (an example of a second external member in this embodiment) and cools the heat generated by the second current passing through the second drain terminal D2.

[0045] (2) Overall layout and configuration of the cooling unit for the rectifier module Next, the arrangement and configuration of the rectifier module 10, the substrate 20, the first conductive cooling section 30, the second conductive cooling section 40, and the cooling promotion section 50 in the cooling unit 100 for the rectifier module will be summarized and further explained.

[0046] 1 and 2, in the cooling unit 100 of the rectifying element module of this embodiment, the cooling promotion part 50 is disposed at the bottom, and the substrate 20 is erected in a direction perpendicular to the arrangement surface 51 of the cooling promotion part 50 (z direction in this embodiment). On the cooling promotion part 50, the rectifying element module 10 and the second conductive cooling part 40 are disposed on the substrate front surface 21 side with the substrate 20 in between, and the first conductive cooling part 30 is disposed on the substrate back surface 22 side.

[0047] The first conductive cooling part 30 is placed on the cooling promotion part 50 while being in contact with the substrate rear surface 22 and the arrangement surface 51 of the cooling promotion part 50. Although not limited thereto, in the example of Fig. 1 and Fig. 2, the first conductive cooling part 30 is configured in an L-shape in a side view by a first part 31 extending in a plate-like manner along a vertical plane (a plane perpendicular to the xy plane) and a second part 32 extending in a plate-like manner along a horizontal direction (a plane parallel to the xy plane). The first part 31 has a planar first part contact surface 31a in surface contact with the substrate rear surface 22, and the second part 32 has a planar second part contact surface 32a in surface contact with the arrangement surface 51 of the cooling promotion part 50.

[0048] The first module terminal 12c is attached to the substrate 20 at a first attachment portion 25, and penetrates the substrate 20 in the thickness direction (x direction) from the substrate front surface 21 to the substrate back surface 22. The first attachment portion 25 faces at least a part of the first portion 31 across the substrate 20. Specifically, the first portion 31 is located at a portion corresponding to the tip of the first module terminal 12c in the extending direction, that is, directly below the first module terminal 12c. The first module terminal 12c is electrically connected to the first portion 31 directly or via solder, and is thus electrically connected to the first conductive cooling part 30 including the first and second portions 31, 32.

[0049] The second conductive cooling part 40 is placed on the cooling promotion part 50 via the insulating member 80 on the substrate surface 21 side. In the example of FIG. 1 and FIG. 2, the second conductive cooling part 40 is configured in a rectangular parallelepiped shape extending in a vertical direction (x direction in FIG. 1) in contact with the substrate surface 21 of the substrate 20, and has a third contact surface 40a (here, the upper surface) on a horizontal plane and a fourth contact surface 40b (here, the lower surface) on a horizontal plane. The insulating member 80 is placed corresponding to a portion of the arrangement surface 51 on which the second conductive cooling part 40 and the substrate 20 are placed. The second conductive cooling part 40 is placed on the cooling promotion part 50 via the insulating member 80 with the fourth contact surface 40b in surface contact with the insulating member 80. The rectifying element module 10 is placed with the second module terminal 13 in surface contact with the third contact surface 40a of the second conductive cooling part 40.

[0050] As described above, the first conductive cooling part 30 is disposed in contact with the rear surface 22 of the substrate, whereas the second conductive cooling part 40 is disposed in contact with the front surface 21 of the substrate. However, the second conductive cooling part 40 is not electrically connected to the substrate 20, and the first conductive cooling part 30 and the second conductive cooling part 40 are not electrically connected to each other. By supporting the substrate 20 by bringing the first and second conductive cooling parts 30, 40 into contact with the substrate 20 from both the front surface 21 and the rear surface 22 of the substrate in this manner, the substrate 20 can be stably erected in a vertical direction relative to the arrangement surface 51 of the cooling promotion part 50.

[0051] The second module terminal 13 is a plate extending along the element body rear surface 11a, and one surface (here, the upper surface) is in surface contact with the element body rear surface 11a. The second module terminal 13 is attached to the second conductive cooling part 40 at the second attachment part 26 with the other surface (here, the lower surface) in surface contact with the third contact surface 40a of the second conductive cooling part 40. At this time, the other surface of the second module terminal 13 is in surface contact with the third contact surface 40a of the second conductive cooling part 40 with the first module terminal 12c extending in a direction perpendicular to the substrate 20. The element body rear surface 11a, the second module terminal 13, the second conductive cooling part 40, the insulating member 80, and the cooling promotion part 50 are in surface contact with each other.

[0052] In this embodiment, as shown in Fig. 2, a plurality of rectifier modules 10 are arranged side by side in the y direction on the substrate surface 21. Each rectifier module 10 has a first or second transistor Q1, Q2 as appropriate. The configuration and arrangement of each rectifier module 10 are the same as those described above.

[0053] (3) Current Path Next, a description will be given of the current flow in the cooling unit 100 of the rectifier module. Whether the first transistor Q1 or the second transistor Q2 is arranged inside the rectifier module 10, the current flow in the cooling unit 100 of the rectifier module is the same.

[0054] FIG. 5 is a current path diagram showing the flow of current in the cooling unit of the rectifier module of FIG. A part of a first current path 60 of a first current from the first source terminal S1 (or the second source terminal S2) through the first module terminal 12c and the first conductive cooling unit 30 to the secondary output (-) line Vout(-) (an example of a first external member in this embodiment) is composed of a first through current path 61 through which the first current penetrates the substrate 20 from the substrate front surface 21 to the substrate rear surface 22. The length of the first through current path 61 is equal to the thickness t of the substrate 20 from the substrate front surface 21 to the substrate rear surface 22. In addition, a part of the first current path 60 further includes a first conductive cooling path 62 through which the first current passes through the first conductive cooling unit 30.

[0055] A portion of the second current path 70 of the second current from the first drain terminal D1 (or the second drain terminal D2) through the second module terminal 13 and the second conductive cooling part 40 to the second partial winding 2d (or the first partial winding 2c) (an example of the second external member in this embodiment) is configured by a second conductive cooling path 72 through which the second current passes through the second conductive cooling part 40 without passing through the substrate 20.

[0056] When the first transistor Q1 is on and the second transistor Q2 is off, a signal from the secondary output (-) line Vout(-) is transmitted as a first current to the first source terminal S1 via a first current path 60 including a first through current path 61 and a first conductive cooling path 62, and a current flows from the first source terminal S1 to the first drain terminal D1. Next, a second current flows from the first drain terminal D1 to the second portion winding end end 2d2 of the second partial winding 2d via a second current path 70 including a second conductive cooling path 72. Then, an output voltage induced in the second partial winding 2d is output from the second portion winding start end 2d1 and the secondary output (+) line Vout(+).

[0057] On the other hand, when the second transistor Q2 is on and the first transistor Q1 is off, a signal from the secondary output (-) line Vout(-) is transmitted as a first current to the second source terminal S2 via the first current path 60 including the first through current path 61 and the first conductive cooling path 62, and a current flows from the second source terminal S2 to the second drain terminal D2. Next, a second current flows from the second drain terminal D2 to the first partial winding start end 2c1 of the first partial winding 2c via the second current path 70 including the second conductive cooling path 72. Then, an output voltage induced in the first partial winding 2c is output from the first partial winding end end 2c2 and the secondary output (+) line Vout(+).

[0058] (4) Effects (4-1) Effects of the above current paths and layout According to the above configuration, the first module terminal 12c can be attached to the substrate 20 in the standard state of the rectifier module 10 when the first module terminal 12c is not bent, thereby eliminating or reducing the effort required for bending.

[0059] Furthermore, according to the above configuration, a part of the first current path 60 extending from the first and second source terminals S1, S2 (first element terminals) through the first module terminal 12c and the first conductive cooling unit 30 to the secondary output (-) line Vout(-) (an example of a first external member in this embodiment) is formed by the first through current path 61, so that heat generation in the substrate 20 due to the first current flowing through the substrate 20 can be suppressed compared to a case in which the entire first current path 60 is formed as wiring on the substrate 20. In other words, by reducing the length of the wiring through which the first current flows in the substrate 20, heat generation in the substrate 20 due to the first current flowing through the wiring is suppressed.

[0060] In addition, by having the first conductive cooling path 62 formed by the first conductive cooling part 30 take on part of the first current path 60, the wiring length through which the first current flows in the substrate 20 can be reduced, thereby suppressing heat generation in the substrate 20.

[0061] Furthermore, a part of the second current path 70 of the second current that runs from the first and second drain terminals D1, D2 (second element terminals) through the second module terminal 13 and the second conductive cooling unit 40 to the secondary windings 2d, 2c (an example of the second external member in this embodiment) is configured by the second conductive cooling path 72 that is formed by the second conductive cooling unit 40 without passing through the substrate 20. Therefore, compared to the case where the entire second current path 70 is formed as wiring on the substrate 20, heat generation in the substrate 20 due to the second current flowing through the substrate 20 can be suppressed.

[0062] Moreover, heat generated by the first and second transistors Q1, Q2 (rectifying elements) due to the first current from the first and second source terminals S1, S2 (first element terminals) is cooled by the first conductive cooling unit 30, while heat generated by the first and second transistors Q1, Q2 (rectifying elements) due to the second current from the first and second drain terminals D1, D2 (second element terminals) is cooled by the second conductive cooling unit 40. Thus, heat generated by the first and second transistors Q1, Q2 (rectifying elements) and the substrate 20 due to the first and second currents can be cooled while preventing short-circuiting between the first and second source terminals S1, S2 (first element terminals) and the first and second drain terminals D1, D2 (second element terminals).

[0063] In this way, when the rectifier module 10 such as a discrete component is attached to the substrate 20 in a standard state in which the first module terminal 12c is not bent, the heat generation of the substrate 20 due to the passage of the first and second currents can be suppressed, and even if the substrate 20 generates heat, the heat can be cooled by the first and second conductive cooling parts 30, 40. Therefore, the first and second transistors Q1, Q2 (rectifier elements) can be suppressed from generating heat due to the influence of the heat generated by the substrate 20. In addition, the heat generated by the first and second transistors Q1, Q2 (rectifier elements) themselves can be cooled by the first and second conductive cooling parts 30, 40. Therefore, the destruction of the first and second transistors Q1, Q2 (rectifier elements) due to the junction temperature becoming high can be suppressed. As described above, the substrate 20 and the first and second transistors Q1, Q2 (rectifier elements) can be cooled while maintaining the standard state of the rectifier element module 10 because the first and second source terminals S1, S2 (first element terminals) of the first and second transistors Q1, Q2 (rectifier elements) are connected to the first module terminal 12c extending outside the element body 11, while the first and second drain terminals D1, D2 (second element terminals) of the first and second transistors Q1, Q2 (rectifier elements) are separately connected to the second module terminal 13 in contact with the back surface 11a of the element body. In this aspect of the rectifier module 10, by arranging the rectifier module 10, the substrate 20, the first conductive cooling section 30, the second conductive cooling section 40, and the cooling promotion section 50 as described above, heat generated by the substrate 20 and the first and second transistors Q1, Q2 (rectifier elements) due to the first and second currents as described above can be efficiently cooled by the first conductive cooling section 30, the second conductive cooling section 40, and the cooling promotion section 50. As described above, according to the present embodiment, it is possible to provide a cooling unit 100 for a rectifier module for cooling the substrate 20 and the first and second transistors Q1, Q2 (rectifier elements).

[0064] Furthermore, the substrate 20 and the first conductive cooling part 30 are in surface contact with each other via the substrate rear surface 22 and the first partial contact surface 31a. Therefore, the substrate 20 can be cooled more efficiently by the first conductive cooling part 30 than in the case of point contact. Furthermore, the first conductive cooling part 30 and the cooling promotion part 50 are in surface contact with each other via the second partial contact surface 32a and the arrangement surface 51. Therefore, the cooling of the first conductive cooling part 30 can be promoted more efficiently by the cooling promotion part 50 than in the case of point contact.

[0065] Further, the element body 11 and the second module terminal 13 are in surface contact with each other through the element body back surface 11a and one surface of the second module terminal 13, while the second module terminal 13 and the second conductive cooling part 40 are in surface contact with each other through the other surface of the second module terminal 13 and the third contact surface 40a. Therefore, the element body 11 can be cooled more efficiently by the second conductive cooling part 40 than in the case of point contact. Furthermore, the second conductive cooling part 40 and the cooling promotion part 50 are in surface contact with each other through the insulating member 80 through the fourth contact surface 40b and the arrangement surface 51. Therefore, the cooling of the second conductive cooling part 40 can be promoted more efficiently by the cooling promotion part 50 than in the case of point contact. Note that the second conductive cooling part 40 is insulated from the substrate 20 but is arranged in contact with the substrate 20, so that the substrate 20 can also be cooled by the second conductive cooling part 40.

[0066] Furthermore, by suppressing the heat generation from the substrate 20 and the first and second transistors Q1 and Q2 (rectifier elements), the temperatures of the first conductive cooling part 30 and the second conductive cooling part 40 are also reduced. Therefore, the DC resistance Rdc of the first and second conductive cooling parts 30 and 40 can be reduced. This reduces the conductive loss (I 2 Rdc, power loss) can be suppressed, so that the power conversion efficiency of the power conversion device 1 can be improved.

[0067] (4-2) Effects of the board being installed vertically According to the above configuration, the cooling promotion unit 50 is vertically erected. The first conductive cooling unit 30 on the rear surface 22 side of the substrate 20 and the second conductive cooling unit 40 on the front surface 21 side of the substrate 20 are arranged to face each other across the substrate 20. With this arrangement, by attaching the first module terminal 12c to the erected substrate 20 in a standard unbent state, the first current passing from the first module terminal 12c to the rear surface 22 side of the substrate can be guided by the first conductive cooling unit 30 to the secondary output (-) line Vout(-) (an example of a first external member in this embodiment) and the heat generated by the first current can be cooled by the first conductive cooling unit 30, while the second current passing through the second module terminal 13 arranged away from the substrate 20 on the front surface 21 side of the substrate can be guided by the second conductive cooling unit 40 to the secondary windings 2d, 2c (an example of a second external member in this embodiment) and the heat generated by the second current can be cooled by the second conductive cooling unit 40.

[0068] (4-3) Effects of the first mounting part facing the first conductive cooling part According to the above configuration, the first mounting portion 25 faces the first conductive cooling portion 30 via the substrate 20, so that the first module terminal 12c can be connected to the first conductive cooling portion 30 via the first through current path 61 at the first mounting portion 25 without via wiring on the substrate 20. This makes it possible to sufficiently suppress heat generation in the substrate 20 due to the first current flowing through the substrate 20. As a result, it is possible to sufficiently suppress damage to the first and second transistors Q1 and Q2 (rectifying elements) due to heat generation in the substrate 20.

[0069] (4-4) Effects of the rectifier module forming the secondary circuit of the transformer In the above embodiment, the first external member is the secondary output line (secondary output (-) line Vout(-)) of the transformer 2, and the second external member is the secondary windings 2c, 2d of the transformer 2. The rectifier element module 10 constitutes the secondary circuit 4 of the transformer 2, through which a large current flows and which is prone to generate large amounts of heat. As described above, a part of the first current path 60 of the first current flowing through the first and second source terminals S1, S2 (first element terminals) is constituted by the first through current path 61, so that the heat generation of the substrate 20 itself and the heat generation of the first and second transistors Q1, Q2 (rectifier elements) can be suppressed. In addition, the heat generation of the substrate 20 itself and the heat generation of the first and second transistors Q1, Q2 (rectifier elements) can also be suppressed by the part of the first current path 60 being constituted by the first conductive cooling section 30, i.e., the first conductive cooling path 62. In addition, since a part of the second current path 70 of the second current flowing through the first and second drain terminals D1, D2 (second element terminals) is configured by the second conductive cooling part 40, i.e., the second conductive cooling path 72, it is possible to suppress heat generation from the substrate 20 and the first and second transistors Q1, Q2 (rectifier elements). Therefore, the cooling unit 100 of the rectifier module described above is useful when applied to the secondary circuit 4 of the transformer 2.

[0070] As another example, for example, the following can be given: the first external member is a secondary winding of the transformer 2, and the second external member is a secondary output line of the transformer 2. As another example, the first external member and the second external member are secondary output lines of the transformer 2, and the polarities of the respective output lines are different.

[0071] As described above, the embodiment of the present invention has been disclosed in the above description, but the present invention is not limited thereto. In other words, various modifications can be made to the above-described embodiments in terms of mechanism, shape, material, quantity, position, arrangement, etc. without departing from the scope of the technical idea and purpose of the present invention, and these are included in the present invention.

[0072] 2. Variations 2-1. Example of Modification of Cooling Unit of Rectifier Module In the above embodiment, the cooling unit 100 for the rectifying element module shown in Figures 1 and 2 has been taken as an example for explanation. However, the cooling unit for the rectifying element module is not limited to this, and may be, for example, a cooling unit for a rectifying element module described below.

[0073] (1) Another aspect of the entire cooling unit of the rectifier module (1-1) Another aspect 1 A cooling unit 100A of a rectifier module according to another aspect 1 of the embodiment of the present invention will be described. FIG. 6A is a side view of the cooling unit of a rectifier module according to another aspect 1 of the embodiment of the present invention. The cooling unit 100A of the rectifier module is different from the cooling unit 100 of the rectifier module shown in FIG. 1 in the arrangement position of the insulating member 80. Only the difference will be described below. In the cooling unit 100 of the rectifier module, the insulating member 80 is arranged between the second conductive cooling unit 40 and the substrate 20 and the cooling promotion unit 50, but in the cooling unit 100A of the rectifier module, the insulating member 80 is arranged between the first conductive cooling unit 30 and the substrate 20 and the cooling promotion unit 50. The first conductive cooling unit 30 and the second conductive cooling unit 40 are electrically insulated from each other, except for the arrangement position of the insulating member 80.

[0074] (1-2) Another aspect 2 A cooling unit 100B of a rectifier module of another aspect 2 according to an embodiment of the present invention will be described. FIG. 6B is a side view of the cooling unit of a rectifier module of another aspect 2 according to an embodiment of the present invention. The cooling unit 100B of the rectifier module is different from the cooling unit 100 of the rectifier module shown in FIG. 1 in the arrangement position of the cooling promotion part 50. Only the difference will be described below. In the cooling unit 100 of the rectifier module, the first conductive cooling part 30 and the second conductive cooling part 40 are arranged on the arrangement surface 51 of the cooling promotion part 50, but in the cooling unit 100B of the rectifier module, only the second conductive cooling part 40 is directly arranged on the arrangement surface 51 of the cooling promotion part 50 without the insulating member 80. The substrate 20 and the first conductive cooling part 30 are not arranged on the arrangement surface 51. The first conductive cooling part 30 and the second conductive cooling part 40 are electrically insulated from each other.

[0075] (1-3) Another aspect 3 A cooling unit 100C for a rectifying element module according to another aspect 3 of the embodiment of the present invention will be described. Fig. 6C is a side view of the cooling unit for a rectifying element module according to another aspect 3 of the embodiment of the present invention. The cooling unit 100C for a rectifying element module differs from the cooling unit 100 for the rectifying element module shown in Fig. 1 mainly in that the substrate 20 is arranged in a horizontal direction. Only the differences will be described below.

[0076] In the cooling unit 100C of the rectifier module, a first conductive cooling part 30 having a rectangular parallelepiped shape is arranged on the arrangement surface 51 of the cooling promotion part 50. The upper surface of the first conductive cooling part 30 is a horizontal plane, and the substrate 20 is arranged horizontally on the first conductive cooling part 30 with the upper surface of the first conductive cooling part 30 and the substrate rear surface 22 in surface contact. In addition, a second conductive cooling part 40 having an L-shape in side view is arranged on the arrangement surface 51 via an insulating member 80. The second conductive cooling part 40 extends upward from a portion in contact with the insulating member 80, and then bends and extends to a position where it overlaps with the upper part of the substrate 20. At the position where it overlaps with the upper part of the substrate 20, the second conductive cooling part 40 has a fifth contact surface 40c along a vertical plane.

[0077] In a standard state, the first module terminal 12c extends perpendicular to the substrate surface 21 (vertical direction (z direction) in the example of FIG. 6B) along the element body rear surface 11a. The element body 11 and the second module terminal 13 are positioned vertically farther from the substrate surface 21 than the first module terminal 12c. At this time, the element body rear surface 11a of the element body 11 is along a vertical plane. The element body 11 and the second module terminal 13 are in surface contact with each other via the element body rear surface 11a and one surface of the second module terminal 13. The second module terminal 13 and the second conductive cooling part 40 are in surface contact with each other via the other surface of the second module terminal 13 and the fifth contact surface 40c.

[0078] (2) Modifications of each part of the cooling unit of the rectifier module (2-1) In the above embodiment, the first conductive cooling part 30 is configured to be L-shaped in side view by the first part 31 extending in a plate shape along the substrate back surface 22 and the second part 32 extending in a plate shape along the arrangement surface 51 of the cooling promotion part 50. However, the first conductive cooling part 30 is only required to electrically connect the first module terminal 12c and the secondary output (-) line Vout(-) and to cool the heat generated by the first current, and the shape is not limited. For example, the first conductive cooling part 30 may be a rectangular parallelepiped in contact with the substrate back surface 22 and the arrangement surface 51. Moreover, the second conductive cooling part 40 is rectangular parallelepiped, but is not limited thereto, and may be, for example, L-shaped in side view.

[0079] (2-2) In the above embodiment, the first portion 31 of the first conductive cooling part 30 extending along the substrate back surface 22 is located at a portion corresponding to the tip of the first module terminal 12c. However, the portion corresponding to the tip of the first module terminal 12c and the first portion 31 may be somewhat separated from each other as long as the adverse effects of heat generation due to the first current, such as destruction of the rectifying elements, can be suppressed. For example, the first mounting portion 25 and the first portion 31 may be somewhat separated from each other in the z direction. In this case, a wiring that electrically connects the separated portion between the first mounting portion 25 and the first portion 31 may be formed on the substrate front surface 21 or the substrate back surface 22. It is preferable that the wiring is short in order to suppress heat generation of the substrate 20 due to the passage of the first current.

[0080] (2-3) In the above embodiment, the second conductive cooling part 40 is disposed in contact with the substrate surface 21. However, the second conductive cooling part 40 does not have to be in contact with the substrate 20 as long as it can electrically connect the second module terminal 13 and the secondary windings 2c, 2d and cool the heat generated by the second current.

[0081] (2-4) In the above embodiment, the rectifier module 10 has three pins: the gate pin 12a, the unused pin 12b, and the first module terminal 12c. However, the number of pins of the rectifier module 10 is not limited. In the above embodiment, the unused pins 12b are configured to be shorter than the gate pins 12a and the first module terminals 12c. However, the unused pins 12b may also be configured to be longer. Since the unused pins 12b are not used, they are inserted into the pin holes of the substrate 20 but are not electrically connected to the substrate 20 or other components.

[0082] 2-2. Another example of a power conversion device including a synchronous rectifier circuit In the above embodiment, the power conversion device including the synchronous rectifier circuit shown in Fig. 3 is taken as an example. However, the power conversion device is not limited to this, and may be, for example, the power conversion device described below.

[0083] (1) Synchronous rectification circuit of alternative configuration 1 A power converter 1A having a synchronous rectifier circuit of another configuration 1 will be described. FIG. 7 is a circuit diagram of a power converter having a synchronous rectifier circuit of another configuration 1. The power converter 1A shown in FIG. 7 is a midpoint tap type and includes a transformer 2, a primary circuit 3, and a secondary circuit 4A. The power converter 1A is different from the power converter 1 of FIG. 1 mainly in that the first portion winding start end 2c1 and the second portion winding end end 2d2 are connected to the secondary output (+) line Vout(+) via the secondary circuit 4A, and the connection part between the first portion winding end end 2c2 and the second portion winding start end 2d1 is connected to the secondary output (-) line Vout(-). The other configurations of the power converter 1A are the same as those of the power converter 1. The differences will be further described below.

[0084] The first drain terminal D1 and the second drain terminal D2 are connected to the secondary output (+) line Vout(+) (an example of the second external member in the configuration of FIG. 7). The first source terminal S1 and the second source terminal S2 are connected to the secondary windings 2c, 2d (an example of the first external member in the configuration of FIG. 7). Specifically, the first source terminal S1 is connected to the first portion winding start end 2c1, and the second source terminal S2 is connected to the second portion winding end end 2d2. The third gate terminal G3 and the fourth gate terminal G4 are respectively input with a first gate signal g1 and a second gate signal g2. The first and second transistors Q1 and Q2 are included in different rectifier modules 10, similarly to the above-described embodiment.

[0085] When the first transistor Q1 is on and the second transistor Q2 is off, a signal from the secondary output (-) line Vout(-) is supplied to the first partial winding end 2c2 of the first partial winding 2c. An output voltage induced in the first partial winding 2c flows as a first current from the first partial winding start end 2c1 through a first current path 60 including a first through current path 61 and a first conductive cooling path 62 to the first source terminal S1. Then, a second current flows from the first drain terminal D1 through a second current path 70 including a second conductive cooling path 72, and an output voltage is output from the secondary output (+) line Vout(+).

[0086] On the other hand, when the second transistor Q2 is on and the first transistor Q1 is off, a signal from the secondary output (-) line Vout(-) is supplied to the second partial winding start end 2d1 of the second partial winding 2d. An output voltage induced in the second partial winding 2d flows as a first current from the second partial winding end 2d2 through the first current path 60 including the first through current path 61 and the first conductive cooling path 62 to the second source terminal S2. Then, a second current flows from the second drain terminal D2 through the second current path 70 including the second conductive cooling path 72, and an output voltage is output from the secondary output (+) line Vout(+).

[0087] (2) Synchronous rectification circuit of alternative configuration 2 A power conversion device 1B having a synchronous rectifier circuit of another configuration 2 will be described. FIG. 8 is a circuit diagram of a power conversion device having a synchronous rectifier circuit of another configuration 2. The power conversion device 1B shown in FIG. 8 is of a full-bridge type and includes a transformer 2, a primary side circuit 3, and a secondary side circuit 4B. The power conversion device 1B is different from the power conversion device 1 of FIG. 1 mainly in the configuration of the secondary side circuit 4B, that is, a secondary side winding 2e is provided instead of the secondary side windings 2c and 2d. The other configurations of the power conversion device 1B are the same as those of the power conversion device 1. The differences will be further described below.

[0088] The secondary circuit 4B has first to fourth transistors Q1 to Q4. The first and fourth transistors Q1, Q4 and the second and third transistors Q2, Q3 are alternately turned on and off. The first and second transistors Q1, Q2 are connected in series, and the first source terminal S1 is connected to the second drain terminal D2. The third and fourth transistors Q3, Q4 are connected in series, and the third source terminal S3 is connected to the fourth drain terminal D4.

[0089] The first drain terminal D1 is connected to the secondary output (+) line Vout(+) (an example of the second external member in the configuration of FIG. 8). The first source terminal S1 is connected to the secondary winding 2e (an example of the first external member in the configuration of FIG. 8). Specifically, the first source terminal S1 is connected to the secondary winding start end 2e1. A first gate signal g1 is input to the first gate terminal G1.

[0090] The second drain terminal D2 is connected to the secondary winding 2e (an example of the second external member in the configuration of FIG. 8). Specifically, the second drain terminal D2 is connected to the secondary winding starting end 2e1. The second source terminal S2 is connected to the secondary output (-) line Vout(-) (an example of the first external member in the configuration of FIG. 8). A second gate signal g2 is input to the second gate terminal G2.

[0091] The third drain terminal D3 is connected to the secondary output (+) line Vout(+) (an example of the second external member in the configuration of FIG. 8). The third source terminal S3 is connected to the secondary winding 2e (an example of the first external member in the configuration of FIG. 8). Specifically, the third source terminal S3 is connected to the secondary winding end 2e2. A second gate signal g2 is input to the third gate terminal G3.

[0092] The fourth drain terminal D4 is connected to the secondary winding 2e (an example of the second external member in the configuration of FIG. 8). Specifically, the fourth drain terminal D4 is connected to the secondary winding end 2e2. The fourth source terminal S4 is connected to the secondary output (-) line Vout(-) (an example of the first external member in the configuration of FIG. 8). The first gate signal g1 is input to the fourth gate terminal G4. The first to fourth transistors Q1 to Q4 are included in different rectifier element modules 10, similarly to the above-described embodiment.

[0093] When the first and fourth transistors Q1 and Q4 are on and the second and third transistors Q2 and Q3 are off, a signal from the secondary output (-) line Vout(-) is transmitted as a first current to the fourth source terminal S4 via the first current path 60 including the first through current path 61 and the first conductive cooling path 62, and a current flows from the fourth source terminal S4 to the fourth drain terminal D4. Then, a second current flows from the fourth drain terminal D4 to the secondary winding end 2e2 of the secondary winding 2e via the second current path 70 including the second conductive cooling path 72. The output voltage induced in the secondary winding 2e is transmitted as a first current from the secondary winding start end 2e1 to the first source terminal S1 via the first current path 60 including the first through current path 61 and the first conductive cooling path 62, and a current flows from the first source terminal S1 to the first drain terminal D1. Then, a second current flows from the first drain terminal D1 through a second current path 70 including a second conductive cooling path 72, and is output as an output voltage from the secondary output (+) line Vout(+).

[0094] On the other hand, when the second and third transistors Q2, Q3 are on and the first and fourth transistors Q1, Q4 are off, a signal from the secondary output (-) line Vout(-) is transmitted as a first current to the second source terminal S2 via the first current path 60 including the first through current path 61 and the first conductive cooling path 62, and a current flows from the second source terminal S2 to the second drain terminal D2. Then, a second current flows from the second drain terminal D2 to the secondary winding start end 2e1 of the secondary winding 2e via the second current path 70 including the second conductive cooling path 72. The output voltage induced in the secondary winding 2e is transmitted as a first current from the secondary winding end end 2e2 to the third source terminal S3 via the first current path 60 including the first through current path 61 and the first conductive cooling path 62, and a current flows from the third source terminal S3 to the third drain terminal D3. Then, a second current flows from the third drain terminal D3 through a second current path 70 including a second conductive cooling path 72, and is output as an output voltage from the secondary output (+) line Vout(+).

[0095] (3) Synchronous rectification circuit of alternative configuration 3 A power conversion device 1C having a synchronous rectifier circuit of another configuration 3 will be described. FIG. 9 is a circuit diagram of a power conversion device having a synchronous rectifier circuit of another configuration 3. The power conversion device 1C shown in FIG. 9 is a forward type, and includes a transformer 2, a primary side circuit 3, and a secondary side circuit 4C. The power conversion device 1C is provided with a secondary side winding 2e instead of the secondary side windings 2c and 2d, and is mainly different in the connection between the secondary side winding 2e and the first and second transistors Q1 and Q2. The other configurations of the power conversion device 1C are the same as those of the power conversion device 1. The differences will be further described below.

[0096] The first drain terminal D1 is connected to the secondary output (+) line Vout(+) (an example of the second external member in the configuration of FIG. 9). The first source terminal S1 is connected to the secondary winding 2e (an example of the first external member in the configuration of FIG. 9). Specifically, the first source terminal S1 is connected to the secondary winding start end 2e1. A first gate signal g1 is input to the first gate terminal G1.

[0097] The second drain terminal D2 is connected to the secondary output (+) line Vout(+) (an example of the second external member in the configuration of FIG. 9). The second source terminal S2 is connected to the secondary winding 2e (an example of the first external member in the configuration of FIG. 9) and the secondary output (-) line Vout(-) (an example of the first external member in the configuration of FIG. 9). Specifically, the second source terminal S2 is connected to the secondary winding end 2e2 and the secondary output (-) line Vout(-). A second gate signal g2 is input to the second gate terminal G2. The first and second transistors Q1 and Q2 are included in different rectifier modules 10, similarly to the above-described embodiment.

[0098] When the first transistor Q1 is on and the second transistor Q2 is off, a signal from the secondary output (-) line Vout(-) is supplied to the secondary winding end 2e2 of the secondary winding 2e. The output voltage induced in the secondary winding 2e is transmitted as a first current from the secondary winding start end 2e1 through a first current path 60 including a first through current path 61 and a first conductive cooling path 62 to a first source terminal S1, and a current flows from the first source terminal S1 to a first drain terminal D1. Then, a second current flows from the first drain terminal D1 through a second current path 70 including a second conductive cooling path 72, and an output voltage is output from the secondary output (+) line Vout(+).

[0099] On the other hand, when the second transistor Q2 is on and the first transistor Q1 is off, the secondary output (-) line Vout(-) and the secondary output (+) line Vout(+) are conductive via the second transistor Q2.

[0100] (4) Synchronous rectification circuit of alternative configuration 4 A power conversion device 1D having a synchronous rectifier circuit of another configuration 4 will be described. FIG. 10 is a circuit diagram of a power conversion device having a synchronous rectifier circuit of another configuration 4. The power conversion device 1D shown in FIG. 10 is a forward type, and includes a transformer 2, a primary side circuit 3, and a secondary side circuit 4D. The power conversion device 1D differs from the power conversion device 1C of FIG. 9 mainly in the connection between the secondary side winding 2e and the first and second transistors Q1, Q2. The other configurations of the power conversion device 1D are similar to those of the power conversion device 1C. The differences will be further described below.

[0101] The first drain terminal D1 is connected to the secondary winding 2e (an example of the second external member in the configuration of FIG. 10). Specifically, the first drain terminal D1 is connected to the secondary winding end 2e2. The first source terminal S1 is connected to the secondary output (-) line Vout(-) (an example of the first external member in the configuration of FIG. 10). A first gate signal g1 is input to the first gate terminal G1.

[0102] The second drain terminal D2 is connected to the secondary output (+) line Vout(+) (an example of the second external member in the configuration of FIG. 10) and the secondary winding 2e (an example of the second external member in the configuration of FIG. 10). Specifically, the second drain terminal D2 is connected to the secondary output (+) line Vout(+) and the secondary winding starting end 2e1. The second source terminal S2 is connected to the secondary output (-) line Vout(-) (an example of the first external member in the configuration of FIG. 10). A second gate signal g2 is input to the second gate terminal G2. The first and second transistors Q1 and Q2 are included in different rectifier modules 10, similarly to the above-described embodiment.

[0103] When the first transistor Q1 is on and the second transistor Q2 is off, a signal from the secondary output (-) line Vout(-) is transmitted as a first current to the first source terminal S1 via a first current path 60 including a first through current path 61 and a first conductive cooling path 62, and a current flows from the first source terminal S1 to a first drain terminal D1. A second current flows from the first drain terminal D1 via a second current path 70 including a second conductive cooling path 72, and is supplied to a secondary winding end 2e2 of the secondary winding 2e. Then, an output voltage induced in the secondary winding 2e is output from a secondary winding start end 2e1 to the secondary output (+) line Vout(+).

[0104] On the other hand, when the second transistor Q2 is on and the first transistor Q1 is off, the secondary output (-) line Vout(-) and the secondary output (+) line Vout(+) are conductive via the second transistor Q2.

[0105] (5) Rectifier circuit In the above embodiment, the secondary circuit 4 includes a synchronous rectifier circuit using the first and second transistors Q1 and Q2. However, the secondary circuit 4 may include a rectifier circuit instead of the synchronous rectifier circuit as long as it can rectify the output voltage induced in the secondary windings 2c and 2d. The rectifier circuit includes, for example, a diode (an example of a rectifier element) instead of the first and second transistors Q1 and Q2 as a rectifier element. The diode has an anode (an example of a first element terminal) and a cathode (an example of a second element terminal), and a current flows in the forward direction from the anode to the cathode, but no current flows in the reverse direction from the cathode to the anode. Therefore, the diode performs a switching operation based on the voltage difference applied to the anode and the cathode. The output voltage rectified by the rectification action of this diode is obtained as the output of the rectifier circuit.

[0106] A specific example is the rectifier circuit shown in Fig. 11. Fig. 11 is a circuit diagram of a power conversion device having a rectifier circuit. In FIG. 11, a first diode d1 (an example of a rectifying element) is provided instead of the first transistor Q1, and a second diode d2 (an example of a rectifying element) is provided instead of the second transistor Q2. The first diode d1 has a first anode A1 (corresponding to the first source terminal S1 in FIG. 3) and a first cathode K1 (corresponding to the first drain terminal D1 in FIG. 3). The second diode d2 has a second anode A2 (corresponding to the second source terminal S2 in FIG. 3) and a second cathode K2 (corresponding to the second drain terminal D2 in FIG. 3). The first and second anodes A1 and A2 are commonly connected to the secondary output (-) line Vout(-). The first and second cathodes K1 and K2 are connected to the secondary windings 2c and 2d. Specifically, the first cathode K1 is connected to the second portion winding end 2d2, and the second cathode K2 is connected to the first portion winding start 2c1. A current flows alternately through the first and second diodes d1 and d2, and a rectified output voltage is output from the secondary output (+) line Vout(+). [Explanation of symbols]

[0107] 1, 1A-1D: Power conversion device 2: Transformer 2a: Core 2b: Primary winding 2c, 2d, 2e: Secondary windings 3: Primary side circuit 4, 4A~4D: Secondary circuit 10: Rectifier module 11: Element body 11a: Back of element body 11b: Front of element body 11c: Side of element body 12: 1st extraction terminal 12a: Gate pin 12b: Unused pin 12c: First module terminal 13: Second module terminal 13a: Stop hole 20: Substrate 21: Substrate surface 22: Back of the board 25: First mounting part 26: Second mounting part 30, 40: First and second conductive cooling sections 50: Cooling promotion part 51: Placement surface 60: First current path 61: First through current path 62: First conductive cooling path 70: Second current path 72: Second conductive cooling path 80: Insulating material 100, 100A~100C: Cooling unit for rectifier module A1, A2: First and second anodes D1 to D4: 1st to 4th drain terminals (2nd element terminals) G1~G4: 1st to 4th gate terminals K1, K2: 1st and 2nd cathodes Q1 to Q4: First to fourth transistors (rectifier elements) S1 to S4: 1st to 4th source terminals (1st element terminals) Vin(+): Primary input (+) line Vin(-): Primary side input (-) line Vout(+): Secondary output (+) line Vout(-): Secondary output (-) line d1, d2: 1st and 2nd diodes g1, g2: 1st and 2nd gate signals

Claims

1. A cooling unit for a rectifier module, comprising: a rectifying element module including: an element body having a first element terminal and a second element terminal, and a rectifying element disposed therein for generating a rectified output voltage by a switching operation based on a voltage difference between the first element terminal and the second element terminal; a first module terminal electrically connected to the first element terminal and extending from a portion of the element body other than a rear surface of the element body along the rear surface of the element body to an outside of the element body; and a second module terminal electrically connected to the second element terminal, and at least a portion of which is disposed in contact with the rear surface of the element body; a substrate formed in a plate shape, having a substrate front surface and a substrate back surface, the rectifying element module being disposed on the substrate front surface side, the first module terminal being attached so as to extend in a direction perpendicular to the substrate surface, and the element body and the second module terminal being spaced apart from the substrate surface; a first conductive cooling section that electrically connects a first external member disposed outside the cooling unit of the rectifier element module and the first module terminal, and that mainly cools heat generated by a first current passing through the first element terminal; the first conductive cooling part is an insulated conductive cooling part, electrically connecting a second external member disposed outside the cooling unit of the rectifier element module and the second module terminal, and a second conductive cooling part for mainly cooling heat generated by a second current passing through the second element terminal; a cooling promotion part on which at least one of the first conductive cooling part and the second conductive cooling part is directly or indirectly arranged, and which promotes cooling of at least one of the first conductive cooling part and the second conductive cooling part; Equipped with the first conductive cooling part is disposed in contact with a rear surface of the substrate, the second conductive cooling part is disposed on the front surface side of the substrate, the second module terminal is disposed in contact with the second conductive cooling portion, a part of a first current path of the first current from the first element terminal through the first module terminal and the first conductive cooling part to the first external member is constituted by a first through current path penetrating the substrate from the substrate front surface to the substrate back surface, A cooling unit for a rectifying element module, wherein a portion of a second current path of the second current from the second element terminal through the second module terminal and the second conductive cooling part to the second external member is composed of a second conductive cooling path that passes through the second conductive cooling part without passing through the substrate.

2. 2. A cooling unit for a rectifying element module as described in claim 1, wherein the substrate is erected with the substrate surface and the substrate back surface perpendicular to a surface on which at least one of the first conductive cooling portion and the second conductive cooling portion of the cooling promotion portion is directly or indirectly arranged.

3. 3 . The cooling unit for a rectifier element module according to claim 1 , wherein a first mounting portion where the first module terminal is mounted on the substrate faces at least a portion of the first conductive cooling portion via the substrate.

4. 3. A cooling unit for a rectifier module as described in claim 1 or 2, wherein the first external member is at least one of a secondary winding of a transformer and a secondary output line of a transformer, and the second external member is at least one of a secondary winding of a transformer and a secondary output line of a transformer.

5. 3. A cooling unit for a rectifying element module as described in claim 1 or 2, wherein both the first conductive cooling portion and the second conductive cooling portion are arranged in the cooling promotion portion, and further comprising an insulating member for insulating the first conductive cooling portion from the second conductive cooling portion.

6. the rectifying element is a transistor, 3 . The cooling unit for a rectifying element module according to claim 1 , wherein the first element terminal and the second element terminal are either a drain terminal or a source terminal of the transistor.

7. the rectifying element is a diode, 3 . The cooling unit for a rectifying element module according to claim 1 , wherein the first element terminal and the second element terminal are either an anode or a cathode of the diode, respectively.

Images